The potential impact of the development of offshore wind farms (OWFs) upon seabird populations is a key issue within the current debate on sustainable energy provision. Terns, (Sterna spp. and Sternula albifrons), especially when on their breeding grounds, have emerged as sensitive receptors in many consented and planned OWF projects. To date, information on the interaction of terns with OWFs has remained scant due to a lack of understanding of the foraging ecology of terns especially at specific sites and the inability of standard assessment tools to define the relative use of specific areas by foraging terns